Microbial Community Responses to Alterations in Historical Fire Regimes in Montane Grasslands
- Authors: Gokul, Jarishma K , Matcher, Gwynneth , Dames, Joanna F , Nkangala, Kuhle , Gordijn, Paul J , Barker, Nigel P
- Date: 2023
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440366 , vital:73777 , https://doi.org/10.3390/d15070818
- Description: The influence of fire regimes on soil microbial diversity in montane grasslands is a relatively unexplored area of interest. Understanding the belowground diversity is a crucial stepping-stone toward unravelling community dynamics, nutrient sequestration, and overall ecosystem stability. In this study, metabarcoding was used to unravel the impact of fire disturbance regimes on bacterial and arbuscular mycorrhizal fungal community structures in South African montane grasslands that have been subjected to an intermediate (up to five years) term experimental fire-return interval gradient. Bacterial communities in this study exhibited a shift in composition in soils subjected to annual and biennial fires compared to the controls, with carbon and nitrogen identified as significant potential chemical drivers of bacterial communities. Shifts in relative abundances of dominant fungal operational taxonomic units were noted, with Glomeromycota as the dominant arbuscular mycorrhiza observed across the fire-return gradient. A reduction in mycorrhizal root colonisation was also observed in frequently burnt autumnal grassland plots in this study. Furthermore, evidence of significant mutualistic interactions between bacteria and fungi that may act as drivers of the observed community structure were detected. Through this pilot study, we can show that fire regime strongly impacts bacterial and fungal communities in southern African montane grasslands, and that changes to their usually resilient structure are mediated by seasonal burn patterns, chemical drivers, and mutualistic interactions between these two groups.
- Full Text:
- Date Issued: 2023
Barriers to Implementing Information Communication Technology (ICT) in Managing Small to Medium Tourism Enterprises (SMTEs): the Case of Hogsback, Eastern Cape, South Africa
- Authors: Mxunyelwa,Siyabonga
- Date: 2021
- Subjects: Hogsback, South Africa Small and medium-sized enterprises Small Business Information Communication Technology (ICT) Computer File
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6031 , vital:45083 , https://www.ijicc.net/images/Vol_15/Iss_10/151057_Mxunyelwa_2021_E_R.pdf
- Description: Information Communication Technology is recognised worldwide for its contribution towardsSMTEs development and the economy. However, the level of ICT implementation as a management tool, its contribution and the extent of benefits on SMTEs is a debateable phenomenon. The purpose of this study was to investigate the barriers to the implementation of ICT within the context of small and medium tourism enterprises in Hogsback. Both quantitative and qualitative research methods were applied in this study. Questionnaire interviews were conducted with owner/managers in Hogsback. The stratified sampling methodwas utilised to collect data. The study indicates that (46.2%) of the business respondents wereoperating the accommodation establishments. The findings of the study underscores that (25.6%) of the business owners identified the barriers of ICT appears to be high costs. Further(23.1%) stated that accessing technology was also an impediment. Moreover, the study elucidates that (94.9%) of the SMTE concur that implementation ICT as a management tool helps to meet objectives of the business for the daily operations of the business. It is therefore recommended that ICT be implemented as a management tool for small and medium tourism enterprises. Furthermore, the study recommends that the managers/owners should invest in technology to ensure the success of the SMTEs in all aspects. Furthermore, the study serves asthe basis for future studies in the area of ICT within the SMTE sector
- Full Text:
- Date Issued: 2021
Dimensions and indicators of non-profit financial condition: evidence from South African public universities
- Authors: Bunting, Mark B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150296 , vital:38965 , DOI: https://doi.org/10.4102/sajems.v23i1.2974
- Description: More than three decades of research have failed to achieve convergence on a method for the measurement of non-profit financial condition, with the literature reporting a bewildering array of financial dimensions, and more than 100 ratios and indicators. This article offers a contribution to a broader discourse in non-profit financial analysis by recognising, and taking action in response to, the potential threat to research validity arising from the generally unchallenged presumption that accounting numbers provide a complete, unbiased and error-free representation of an entity’s underlying economic reality.
- Full Text:
- Date Issued: 2020
Effect of a low density dust shell on the propagation of gravitational waves:
- Authors: Bishop, Nigel T , van der Walt, Petrus J , Naidoo, Monos
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159935 , vital:40357 , https://0-doi.org.wam.seals.ac.za/10.1007/s10714-020-02740-9
- Description: Using the Bondi-Sachs formalism, the problem of a gravitational wave source surrounded by a spherical dust shell is considered. Using linearized perturbation theory, the geometry is found in the regions: in the shell, exterior to the shell, and interior to the shell. It is found that the dust shell causes the gravitational wave to be modified both in magnitude and phase, but without any energy being transferred to or from the dust.
- Full Text:
- Date Issued: 2020
Implementation of access and benefit-sharing measures has consequences for classical biological control of weeds:
- Authors: Silvestri, Luciano , Sosa, Alejandro , Mc Kay, Fernando , Vitorino, Marcelo D , Hill, Martin P , Zachariades, Costas , Hight, Stephen , Weyl, Philip S R , Smith, David , Djeddour, Djamila , Mason, Peter G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150285 , vital:38964 , https://link.springer.com/article/10.1007/s10526-019-09988-4
- Description: The Convention on Biological Diversity and the Nagoya Protocol establish that genetic resources shall be accessed only upon the existence of prior informed consent of the country that provides those resources and that benefits arising from their utilization shall be shared. Pursuant to both agreements several countries have adopted regulations on access and benefit-sharing. These regulations have created a challenging obstacle to classical biological control of weeds. This paper reviews the experiences of Argentina, Brazil, South Africa, the USA, Canada and CABI in implementing access and benefit-sharing regulations and the implications these measures have on the effective and efficient access, exchange and utilization of biological control agents.
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- Date Issued: 2020
Influence of intra-and interspecific variation in predator–prey body size ratios on trophic interaction strengths:
- Authors: Cuthbert, Ross N , Wasserman, Ryan J , Dalu, Tatenda , Kaiser, Horst , Weyl, Olaf L F , Dick, Jaimie T A , Sentis, Arnaud , McCoy, Michael W , Alexander, Mhairi E
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149358 , vital:38839 , https://0-doi.org.wam.seals.ac.za/10.1002/ece3.6332
- Description: Predation is a pervasive force that structures food webs and directly influences ecosystem functioning. The relative body sizes of predators and prey may be an important determinant of interaction strengths. However, studies quantifying the combined influence of intra‐ and interspecific variation in predator–prey body size ratios are lacking. We use a comparative functional response approach to examine interaction strengths between three size classes of invasive bluegill and largemouth bass toward three scaled size classes of their tilapia prey. We then quantify the influence of intra‐ and interspecific predator–prey body mass ratios on the scaling of attack rates and handling times.
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- Date Issued: 2020
Integrating livelihoods and forest conservation through beekeeping in northern KwaZulu-Natal:
- Authors: Ricketts, K , Shackleton, Charlie M
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/176358 , vital:42687 , https://doi.org/10.1080/0376835X.2019.1698408
- Description: South Africa has potential to export honey products through promoting beekeeping as an income generating opportunity amongst rural communities. Formalised beekeeping may also reduce wild fires initiated by hunters of wild bee hives. This study examined the contribution of the African Honey Bee (AHB) initiative to rural livelihoods and the incidence of forest fires using a mixed methods approach. The initiative increased incomes of newly trained and active beekeepers, although success rates and honey yields were variable. Core challenges included not catching bees, theft and vandalism of hives, insufficient bee forage, drought and pests. Most respondents also perceived an increase in crop size since AHB began, although few attributed this to pollination from the bees. The number of wild fires attributed to honey hunters more than halved after AHB began. Future steps need to reduce the challenges and integrate beekeeping into broader agriculture and forest conservation programmes.
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- Date Issued: 2020
Intraspecific mitochondrial gene variation can be as low as that of nuclear rRNA:
- Authors: Matumba, Tshifhiwa G , Oliver, Jody , Barker, Nigel P , McQuaid, Christopher D , Teske, Peter R
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160401 , vital:40442 , https://doi.org/10.12688/f1000research.23635.2
- Description: Mitochondrial DNA (mtDNA) has long been used to date historical demographic events. The idea that it is useful for molecular dating rests on the premise that its evolution is neutral. Even though this idea has long been challenged, the evidence against clock-like evolution of mtDNA is often ignored. Here, we present a particularly clear and simple example to illustrate the implications of violations of the assumption of selective neutrality.
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- Date Issued: 2020
Low-frequency observations of the giant radio galaxy NGC 6251:
- Authors: Cantwell, T M , Bray, J D , Croston, J H , Scaife, A M M , Mulcahy, D D , Best, P N , Brüggen, M , Brunetti, G , Callingham, J R , Clarke, A O , Hardcastle, M J , Harwood, J J , Heald, G , Heesen, V , Iacobelli, M , Jamrozy, M , Morganti, R , Orru, E , O’Sullivan, S P , Riseley, C J , Röttgering, H J A , Shulevski, A , Sridhar, S S , Tasse, C , Van Eck, C L
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149931 , vital:38913 , https://0-doi.org.wam.seals.ac.za/10.1093/mnras/staa1160
- Description: We present LOFAR observations at 150 MHz of the borderline FRI/FRII giant radio galaxy NGC 6251. This paper presents the most sensitive and highest resolution images of NGC 6251 at these frequencies to date, revealing for the first time a low-surface-brightness extension to the northern lobe, and a possible backflow associated with the southern lobe. The integrated spectra of components of NGC 6251 are consistent with previous measurements at higher frequencies, similar to results from other LOFAR studies of nearby radio galaxies.
- Full Text:
- Date Issued: 2020
Making visible the affective dimensions of scholarship in postgraduate writing development work
- Authors: Clarence, Sherran
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439495 , vital:73601 , https://doi.org/10.47989/kpdc63
- Description: Many university writing and student academic development centres serve both under-and postgraduate student-writers. However, it is not always clear that the training and development of those who work with writers accounts fully for the affective dimensions of postgraduate writing, specifically. Especially at the doctoral level, where an original contribution to knowledge is required, writers need to take on a confident authorial voice in their work, both written and in conversation with others. Research, however, shows that many doctoral students struggle with this. This paper argues that, to be truly successful and fit for purpose, peer writing development work needs to understand the nature of postgraduate learning and writing from more than just the technical perspective of writing a successful thesis. Writer-focused work at this level needs to account for the affective dimensions of writing and research as well, to engage students in more holistic, critical, and forward-looking conversations about their writing, and their own developing scholarly identity. The paper offers insights into the different affective dimensions of postgraduate writing, especially those under-considered in much practical work with postgraduate writers, and offers suggestions for a whole-student tutoring approach at this level.
- Full Text:
- Date Issued: 2020
Quality by Design Optimization of Cold Sonochemical Synthesis of Zidovudine-Lamivudine Nanosuspensions:
- Authors: Witika, Bwalya A , Smith, Vincent J , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148424 , vital:38738 , https://doi.org/10.3390/pharmaceutics12040367
- Description: Lamivudine (3TC) and zidovudine (AZT) are antiviral agents used to manage HIV/AIDS infection. The compounds require frequent dosing, exhibit unpredictable bioavailability and a side effect profile that includes hepato- and haema-toxicity. A novel pseudo one-solvent bottom-up approach and Design of Experiments using sodium dodecyl sulphate (SDS) and α-tocopheryl polyethylene glycol succinate 1000 (TPGS 1000) to electrosterically stablize the nano co-crystals was used to develop, produce and optimize 3TC and AZT nano co-crystals. Equimolar solutions of 3TC in surfactant dissolved in de-ionised water and AZT in methanol were rapidly injected into a vessel and sonicated at 4 °C.
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- Date Issued: 2020
Researching mobile phones in the everyday life of the “less connected”: the development of a New Diary Method
- Authors: de Lanerolle, Indra , Schoon, Alette , Walton, Marion
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160413 , vital:40443 , DOI: 10.1080/23743670.2020.1813785
- Description: This article introduces our mobile diary method, a qualitative method for the study of mobile phone practices. Adapted from the diary methods of psychology and media studies audience research, it is designed to foreground tacit and mundane data about everyday mobile phone practices. The diary interview reconstructs details of the social practices of everyday life that make up each participant’s “yesterday” and situates mobile practices within this account. To illustrate the method, we provide examples from our study, Izolo, that spanned three distinct South African neighbourhoods in different parts of the country and focused on less-connected people.
- Full Text:
- Date Issued: 2020
The in vitro antiplasmodial and antiproliferative activity of new ferrocene-based α-aminocresols targeting hemozoin inhibition and DNA interaction:
- Authors: Mbaba, Mziyanda , Dingle, Laura M K , Swart, Tarryn , Cash, Devon , Laming, Dustin , de la Mare, Jo-Anne , Taylor, Dale , Hoppe, Heinrich C , Biot, Christophe , Edkins, Adrienne L , Khanye, Setshaba D
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149347 , vital:38827 , https://0-doi.org.wam.seals.ac.za/10.1002/cbic.202000132
- Description: Compounds incorporating ferrocene in a aminocresol scaffold showed antiplasmodial and anticancer activity. SAR studies revealed that an OH group and rotatable C–NH bond are vital for biological activity, with spectrophotometric techniques and docking simulations suggesting a dual mode of action involving hemozoin inhibition and DNA interaction. Targeting multiple pathways could delay the development of clinical resistance.
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- Date Issued: 2020
The privacy paradox applies to IoT devices too: a Saudi Arabian study
- Authors: Aleisa, Noura , Renaud, Karen , Bongiovanni, Ivano
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150252 , vital:38953 , https://doi.org/10.1016/j.cose.2020.101897
- Description: The “privacy paradox” is the term used to describe the disconnect between self-reported privacy value attributions and actions actually taken to protect and preserve personal privacy. This phenomenon has been investigated in a number of domains and we extend the body of research with an investigation in the IoT domain. We presented participants with evidence of a specific IoT device’s (smart plug) privacy violations and then measured changes in privacy concerns and trust, as well as uptake of a range of behavioural responses. Our Saudi Arabian participants, despite expressing high levels of privacy concerns, generally chose not to respond to this evidence with preventative action.
- Full Text:
- Date Issued: 2020
The Privacy Paradox applies to IoT devices too: a Saudi Arabian study
- Authors: Aleisa, Noura , Renaud, Karen , Bongiovanni, Ivano
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158350 , vital:40176 , https://doi.org/10.1016/j.cose.2020.101897
- Description: The “privacy paradox” is the term used to describe the disconnect between self-reported privacy value attributions and actions actually taken to protect and preserve personal privacy. This phenomenon has been investigated in a number of domains and we extend the body of research with an investigation in the IoT domain. We presented participants with evidence of a specific IoT device’s (smart plug) privacy violations and then measured changes in privacy concerns and trust, as well as uptake of a range of behavioural responses.
- Full Text:
- Date Issued: 2020
‘There is nothing to hold onto here’:
- Authors: Shabangu, Samuel M , Babu, Balaji , Soy, Rodah C , Managa, Muthumuni , Sekhosana, Kutloano E , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156410 , vital:39987 , DOI: 10.1080/00958972.2020.1739273
- Description: Asymmetric mono-carboxy-porphyrins, (5-(4-carboxyphenyl)−10,15,20-tris(pentafluorophenyl)porphyrinato zinc(II) (1), 5-(4-carboxyphenyl)−10,15,20-triphenylporphyrinato zinc(II) (2) and 5-(4-carboxyphenyl)−10,15,20-tris(2-thienyl)porphyrinato zinc(II) (3), were linked to Ag nanoparticles (AgNPs) through amide bonds and self-assembly (the latter only for 3). The porphyrins and conjugates were used for photodynamic antimicrobial chemotherapy (PACT) against Staphylococcus aureus. PACT uses singlet oxygen for antimicrobial activity. Complex 3 and its conjugates had higher singlet oxygen quantum yields and higher log reduction when compared with the rest of the porphyrins and corresponding conjugates. These high log reductions for 3 and its conjugate were attributed to the presence of sulfur groups whereby there was more interaction with the bacterial membrane.
- Full Text:
- Date Issued: 2020
In Parenthesis:
- Authors: de Jager, Maureen
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147880 , vital:38681 , DOI: 10.1080/02560046.2019.1684966
- Description: IN PARENTHESIS is a practice-based essay which takes shape, parasitically, amidst the “found text” of an existing book, British author Thomas Pakenham's The Boer War (1979, Johannesburg: Jonathan Ball). The “author-reader” interjects into the found text of this authoritative history book, inserting her words amongst those of Pakenham's. What becomes apparent, however, is that the text into which she interjects is not The Boer War verbatim, but a dramatically abridged version. The book's primary content has been edited out. What remains is The Boer War whittled down to a litany of Pakenham's parentheses (the history book distilled into an essence of the seemingly non-essential). Into this stream of bracketed matter, the author-reader writes, ruminating on the parenthesis as ethos (as prison and portal, barricade and breach, enclave and embrace). In turn, her ruminations invite reflection on the conundrum of writing history, of writing this history (and, indeed, of writing per se).
- Full Text:
- Date Issued: 2019
Movement and predation: a catch-and-release study on the acoustic tracking of bonefish in the Indian Ocean
- Authors: Moxham, Emily Jeanne , Cowley, Paul D , Bennett, Rhett H , von Brandis, Rainer G
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/103946 , vital:32325 , https://doi.org/10.1007/s10641-019-00850-1
- Description: Tourism generated through bonefish (Albula spp.) fishing contributes to the economies of many isolated tropical islands and atolls. However, little research has been conducted on bonefish in the Indian Ocean. This study aimed to contribute to the understanding of bonefish ecology in the Indian Ocean by quantifying the spatial and temporal movements of Albula glossodonta at a near-pristine and predator-rich atoll in the Seychelles; however, to achieve this, an analysis to identify the occurrence of possible post-release predation bias was first necessary. An acoustic telemetry study was initiated at the remote St. Joseph Atoll, within an array of 88 automated data-logging acoustic receivers. Thirty bonefish were surgically implanted with Vemco V13 acoustic transmitters and tracked for one year. Only 10% of the tagged bonefish were detected for longer than two weeks. A comparison of the final 100 h of movement data from fish detected for less than two weeks to the movement data of the fish detected for longer periods revealed distinct differences in area use and significant differences in the average daily distance moved, speed of movement and frequency of detections. This suggested that mortality in the form of post-release predation was at least 43% of tagged fish. The three surviving bonefish were tracked for 210 to 367 days. These individuals remained in the atoll and showed high use of the marginal habitats between the shallow sand flats and the lagoon. A generalised linear mixed model identified that water temperature, diel cycle and tide were significant predictors of bonefish presence in the lagoon. The high post-release mortality highlights that catch-and-release is likely not as benign as previously believed and management and policy should be adjusted accordingly.
- Full Text:
- Date Issued: 2019
‘Yummy or crummy?': the multisensory components of medicines-taking among HIV-positive youth
- Authors: Hodes, Rebecca , Vale, Beth , Toska, Elona , Cluver, Lucie , Dowse, Roslind , Ashorn, Mikael
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156663 , vital:40036 , DOI: 10.1080/17441692.2018.1504103
- Description: The global rollout of Antiretroviral Treatment (ART) has revealed an urgent need to understand the medicines-taking practices of HIV-positive adolescents. In the last decade, the literature on the social determinants of health has broadened the evidence-base on ART adherence. Interdisciplinary studies have expanded conceptions of medicines-taking beyond clinical or health systems frameworks, recognising the importance of socio-structural conditions and of patients’ beliefs and experiences. Participatory research techniques which foreground the perspectives of adolescents provide greater insights still into their adherence. This article explores the use of participatory methods within a broader study on the social determinants of ART adherence among HIV-positive adolescents in South Africa. We describe how participatory methods were incorporated into this study (n = 1,059 in the quantitative baseline). We focus on an exercise, ‘Yummy or crummy?’, that explored the multisensory dimensions of medicines-taking, including their colour, smell, shape, and delivery mechanism. We describe two principal findings: first, adolescents’ preference for greater understanding of the chemical workings of medicines, manifested in their preferences for colour, taste and shape of medicines; and second, the vital relationship between sensory preferences and the social imperatives of discretion and confidentiality regarding HIV-status.
- Full Text:
- Date Issued: 2019
Strangers “at home”: gay, lesbian and bisexual students’ strategies for resisting heteronormativity in university residence life
- Authors: Munyuki, C , Vincent, Louise
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141680 , vital:37996 , DOI: 10.20853/32-3-2521
- Description: Higher education in post-apartheid South Africa has been concerned with the establishment of non-discriminatory institutions. However, research continues to highlight various experiences of exclusionary practices across universities in South Africa. In this article, we demonstrate the various coping mechanisms that some students who self-identify as gay, lesbian or bisexual in the university residences adopt to deal with the exclusionary practices that the dominant heteronormative culture of the institution (re)produces which positions them as “sexual strangers” within the institutional “home”. We adopt Vangelisti and Crumley’s (1998) three categories of behaviour namely “acquiescence” which we term here as endeavours to “fit in”, “invulnerability” which we identify as “keeping one’s distance”, “verbal active” as “voicing” and a fourth category we identify as “turning the tables on heteronormativity” in our discussion. We also highlight the various forms of responses that the institution adopts in its attempts to create a conducive environment for all.
- Full Text:
- Date Issued: 2018